Dishwasher door balancing system

ABSTRACT

A kitchen or household appliance such as a dishwasher includes a base portion, a door hingably connected to the base portion, a cord operatively connected to the door, an extension spring operatively connected to the cord and the base portion to partially balance opening of the door by exerting a force on the cord and the door, a damping pulley positioned along the cord between the extension spring and the door to further balance opening of the door by providing resistance to motion of opening the door without manual adjustment.

BACKGROUND OF THE INVENTION

[0001] This invention relates to household appliances, including, butnot limited to dishwashers. More specifically, this invention relates toa system for balancing the door of the household appliance.

[0002] In household or kitchen appliances, such as dishwashers, it isdesirable to have proper door balance. When there is proper doorbalance, the door can open in a smooth, controlled motion. It isdesirable for an operator to open the door to the desired level with nosudden fall of the door or tendency for the door to spring back up froman open position. Manufacturers have attempted to provide proper doorbalance by manually adjusting the balance of dishwasher doors.

[0003] Adjustment of a dishwasher door is a burden to dishwashermanufacturers. Based on different model features (such as, but notlimited to the control type, the presence of sound dampers, the materialweight, or other variations) the weight of the dishwasher doors willvary. Therefore, in order to provide for proper balancing, each doorassembly requires a specific counterbalance force to provide properadjustment. If there is improper adjustment, a front-loading door canfall hard to a noisy and abrupt stop in the horizontal position, or thedoor may not sit horizontal without the operator having to physicallypush the door down to the fully open position. Thus, improper adjustmentis a nuisance to the consumer. In particular, improper adjustment of adishwasher door is believed to result in a poor quality perception byconsumers of the dishwasher.

[0004] In dishwashers, a set of extension springs are typically used forproviding proper door balance. Then, each extension spring can bemanually adjusted for each dishwasher model in order to provide forproper balancing. One problem is that this adjustment process islabor-intensive, and thus can be cost prohibitive.

[0005] Another attempt is a system wherein a stranded rope runs througha groove in a fixed plastic part to generate friction for restrictingdoor motion. One problem with such an approach is that the stranded ropecan wear and break during normal use due to the wear resulting fromfriction. A broken rope can result in a service call.

[0006] Therefore, a primary object of the present invention is theprovision of an improved household or kitchen appliance, such as adishwasher.

[0007] A further object of the present invention is the provision of adishwasher door that provides for proper adjustment without requiring amanual adjustment process.

[0008] A further object of the present invention is the provision of adishwasher having a door balancing system that provides for smooth,controlled motion of the door.

[0009] Yet another object of the present invention is the provision of adishwasher door balancing system that provides consumers with a highquality perception of the dishwasher.

[0010] A further object of the present invention is the provision of adishwasher door balancing system that allows for variance in the weightof the dishwasher door.

[0011] Yet another object of the present invention is the provision of adishwasher door balancing system that uses frictional force withoutcausing undue wear on the dishwasher.

[0012] These and/or other objects, features, or advantages of thepresent invention will become apparent from the specification and theclaims that follow.

SUMMARY OF THE INVENTION

[0013] The present invention relates to a kitchen or household appliancehaving a door, such as, but not limited to a dishwasher. The presentinvention provides for proper balancing of a dishwasher door withoutrequiring manual adjustment of springs or other manual adjustments tocompensate for the weight of the particular dishwasher door.

[0014] According to one embodiment of the present invention, a kitchenappliance includes a base portion, a door hingably connected to the baseportion, a cord operatively connected to the door, an extension springoperatively connected to the cord and the base portion to partiallybalance opening of the door by exerting a force on the cord and thedoor, and a damping pulley is positioned along the cord between theextension spring and the door to further balance opening of the door byproviding resistance to motion of opening the door without manualadjustment. The extension spring counterbalances most of the doorweight. Then, to account for variance in door weight for differentmodels, the damping pulley system resists motion of the openeddishwasher door. In the damping pulley system, friction is applied toresist rotation at the pulley. The present invention provides forapplying the friction in various ways. Also, the pulley can includeteeth to prevent the slippage of the cord. For example, a flange inoperative contact with the damping pulley can provide resistance tomotion of opening the door. The flange can be a piece of spring steelthat engages a perimeter surface of the damping pulley. The flange canengage a side-wall of the pulley to provide resistance to motion ofopening the door.

[0015] According to another aspect of the present invention, the presentinvention provides for a door balancing system for a dishwasher having acabinet and a door. The door balancing system includes an extensionspring operatively connected to the cabinet, a cord operativelyconnected to the extension spring and the door, and a pulley engagingthe cord between the extension spring and the door such that theextension spring provides a first force to balance opening of the doorand the pulley resists motion of opening the door to further balanceopening of the door.

[0016] According to another aspect of the present invention, afront-loading dishwasher is provided. The front-loading dishwasher has acabinet and a door operatively connected to the cabinet and includes anextension spring operatively connected to the cabinet to provide a forcefor partially counterbalancing weight of the door, a cord operativelyconnected between the extension spring and the door, a damping pulleypositioned along the cord to provide resistance to motion of opening ofthe dishwasher door such that the door opens in a controlled mannerwithout a manual adjustment to alter the force provided by the extensionspring. The dishwasher can include a flange in operative contact withthe damping pulley to increase resistance to the motion of opening thedoor.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]FIG. 1 is a perspective view of a dishwasher.

[0018]FIG. 2 is a side view of the bottom portion of a dishwasher withthe door closed and having a door balancing system with a toothed pulleyaccording to one embodiment of the present invention.

[0019]FIG. 2A is a view similar to FIG. 2, except with the door open.

[0020]FIG. 3 is a side view of a dishwasher door balancing systemaccording to another embodiment of the present invention.

[0021]FIG. 4 is a side view of a dishwasher door balancing systemaccording to another embodiment of the present invention.

[0022]FIG. 5 is a side view of a dishwasher balancing system accordingto another embodiment of the present invention.

[0023]FIG. 6 is a front view of the pulley of the door balancing systemtaken along lines 6-6 of FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention provides for balancing the weight of doorsof a kitchen or household appliance such as a dishwasher. FIG. 1illustrates a dishwasher 10. The dishwasher 10 includes a dishwasherdoor 12 and a dishwasher base portion 14. The dishwasher door 12 ishingably connected to the dishwasher base portion 14, such as along abottom portion of the dishwasher base portion 14. The dishwasher 10shown is a front-loading dishwasher with the door 12 opening outwardlyand downwardly.

[0025]FIG. 2 provides a side view of the bottom portion of thedishwasher 10. In FIG. 2, the dishwasher door 12 is hingably connectedto the dishwasher base portion 14 at the door hinge 16. A stranded rope,cable or other type of cord 18 is also operatively connected to thedishwasher door 12 in any convenient manner. For example, as shown inthe drawings, the forward end of the cord 18 includes a bead or loop,which is received in a notch 32 of an inwardly extending arm 30 of thedoor 12. The rearward end of the cord 18 is connected to an extensionspring 26 that is connected to the dishwasher base portion 14. A pulley20 is located between the extension spring 26 and the dishwasher door12. The cord 18 is in operative contact with the pulley 20. The pulley20 rotates in the direction indicated by arrow 28. The pulley 20 caninclude a plurality of teeth 22 that may be molded into the pulley 20.The pulley 20 is pivotal about a pivot 36, which can be a shoulder bolt.The cord 18 can include catch members such as over molded beads orswaged ferrules 24 that matingly contact between the teeth 22 of thepulley 20. This restricts the motion of the cord 18 in order to reduceor eliminate slippage. Other types of catch members can be used so thatthe cord 18 can matingly contact with the teeth 22 of the pulley 20 inorder to allow smooth opening of the dishwasher door 12.

[0026] The positioning of the cord 18 as shown allows the extensionspring 26 to exert an inwardly directed force on the cord 18 to provideresistance to the motion of opening the dishwasher door 12. FIG. 2Aillustrates the dishwasher door 12 in an open position with theextension spring 26 expanded.

[0027]FIG. 3 shows another embodiment of the present invention. In FIG.3, the cord 18A is wrapped around the pulley 20. Wrapping the cord 18Acompletely around an outer flange 27 of the pulley 20 reduces oreliminates slippage, since there are no beads on the cord 18A.

[0028] The damping system for the pulley 20 can be provided in differentmanners. For example, in FIG. 4, a steel spring flange 34 is inoperative contact with the pulley 20 in order to exert a friction forceon the perimeter edge 27 of the pulley 20. The steel spring flange 34can be operatively connected to the dishwasher base portion 14 with asupport member 38. The steel spring flange 34 provides friction suchthat the pulley resists the motion of opening the door to furtherbalance opening of the door.

[0029] Another embodiment of the present invention is shown in FIGS. 5and 6. In FIGS. 5 and 6, a spider-like steel compression spring 44 ismounted behind pulley 20 at the pivot 36. The spring 44 has multiplelegs 48, each having a substantially flat flange 42 in operative contactwith a flat surface 46 of the pulley 20. This contact exerts africtional force on the pulley 20 to smooth the motion of opening thedoor. In FIG. 6, the pivot 36 consists of a shoulder bolt to pivotallyconnect the pulley to the dishwasher tub support 40 of the dishwasherbase portion 14. Although the present invention contemplates othermanners of providing frictional force for providing balancing,preferably friction is not applied in a manner that will create unduewear and increase the need for servicing.

[0030] Thus, a kitchen or household appliance, such as a dishwasher, hasbeen disclosed that has an extension spring to balance weight of thekitchen appliance door and is adapted for balancing without manualadjustment of the extension spring. The present invention contemplatesthat one or more extension springs and/or damping pulleys can be used.For example, the present invention contemplates that two sets of dampingpulleys and extension springs can be used on opposite sides of adishwasher. The present invention also contemplates variations andequivalents in the manner in which the pulley is dampened. These andother variations and equivalents are within the spirit and scope of thepresent invention.

What is claimed is:
 1. A kitchen appliance, comprising: a base portion;a door hingably connected to the base portion; a cord operativelyconnected to the door; an extension spring operatively connected to thecord and the base portion to partially balance opening of the door byexerting a force on the cord and the door; a damping pulley positionedalong the cord between the extension spring and the door to furtherbalance opening of the door by providing resistance to motion of openingthe door without manual adjustment.
 2. The kitchen appliance of claim 1further comprising a flange in operative contact with the damping pulleyto provide resistance to motion of opening the door.
 3. The kitchenappliance of claim 2 wherein the flange is a spring flange for engaginga perimeter surface of the damping pulley.
 4. The kitchen appliance ofclaim 2 wherein the flange engages a side-wall of the damping pulley. 5.The kitchen appliance of claim 1 wherein the force is an inwardlydirected force.
 6. The kitchen appliance of claim 1 wherein the kitchenappliance is a dishwasher.
 7. The kitchen appliance of claim 1 whereinthe cord is stranded.
 8. The kitchen appliance of claim 1 wherein thedamping pulley includes a plurality of teeth.
 9. The kitchen applianceof claim 8 wherein the cord includes a plurality of catch members. 10.The kitchen appliance of claim 9 wherein the catch members are beads.11. The kitchen appliance of claim 1 wherein the cord is wrappedcompletely around the pulley to reduce slippage.
 12. A door balancingsystem for a dishwasher having a cabinet and a door, the door balancingsystem, comprising: an extension spring operatively connected to thecabinet; a cord operatively connected to the extension spring and to thedoor; a pulley engaging the cord between the extension spring and thedoor such that the extension spring provides a first force to balanceopening of the door and the pulley resists motion of opening the door tofurther balance opening of the door.
 13. The door balancing system ofclaim 12 further comprising a flange in operative contact with thepulley to provide resistance to motion of opening the door.
 14. The doorbalancing system of claim 13 wherein the flange is a spring flange forengaging a perimeter surface of the pulley.
 15. The door balancingsystem of claim 13 wherein the flange engages a side-wall of the pulley.16. The door balancing system of claim 12 wherein the pulley includes aplurality of teeth.
 17. The door balancing system of claim 12 whereinthe cord is wrapped completely around the pulley to reduce slippage. 18.A front-loading dishwasher having a cabinet and a door operativelyconnected to the cabinet, comprising: an extension spring operativelyconnected to the cabinet to provide a force for partiallycounterbalancing weight of the door; a cord operatively connectedbetween the extension spring and the door; a damping pulley positionedalong the cord to provide resistance to motion of opening of thedishwasher door such that the door opens in a controlled manner withouta manual adjustment to alter the force provided by the extension spring.19. The dishwasher of claim 18 further comprising a flange in operativecontact with the damping pulley to increase resistance to the motion ofopening the door.